Many pessimists, I
suspect, adhere to the bad apple theory of warfare. They believe that war keeps
breaking out because the worst among us, the bad apples, invariably drag the
rest of us down to their level. The Yanomamo take this attitude, according to
their chief chronicler, Napoleon Chagnon. "Almost everyone, including the
Yanomamo, regards war as repugnant and would prefer that it did not exist," he
writes. "Like us, they are more than willing to quit--if the bad guys also quit.
If we could all get rid of the bad guys, there wouldn't be any war."According
to this view, even if the vast majority of us are decent, empathetic, and
inclined toward peace, humanity will always be plagued by warmongers like
Genghis Khan, Hitler, and Osama Bin Laden, who have violent ambitions and are
charismatic enough to attract followers, who may be bad apples as well. We good
guys, goes the thinking, must remain armed to protect ourselves against those
bad guys, sometimes with preemptive attacks. By this logic, war and militarism will
never end.

But this assertion
does not withstand scrutiny. A few individuals do indeed seem to be
incorrigibly aggressive, violent, and lacking in empathy for others. Bad
apples. Fine. But war itself, rather than an innate lust for violence, turns
most people into bad guys. When peace breaks out, bad guys are magically transformed
into good guys, as history has demonstrated over and over again. England,
France, Spain, Germany, and other European states clashed violently for
centuries, but war between these members of the European Union has become
unimaginable. My father, who as a young man fought the Japanese, now drives a
Japanese car and watches a Japanese television. He and my sister Patty have
vacationed in Vietnam, and my daughter Skye has a friend whose parents are
Vietnamese-American.

Biological
theories of war have inspired a slew of bio-solutions, which aim to repress, vent,
or redirect our allegedly innate urge to fight. One of the most radical was
proposed in the late 1960s by the Yale neurophysiologist Jose Delgado. Delgado,
ironically, was one of the original signers of the Seville Statement, which
repudiates biological theories of war. But he suggested that war and other
forms of violence could be curbed by implanting radio-controlled electrodes in
peoples' brains.

Delgado was the
pioneer -- and flamboyant promoter - of this technology. In 1963, he stood in a
Spanish bullring as a bull with a radio-equipped array of electrodes implanted
in its brain charged toward him. Delgado pushed a button on a radio transmitter,
causing the "stimoceiver" to zap a region in the bull's brain supposedly
associated with aggression. The bull stopped in its tracks and trotted away.
The media marveled at Delgado's transformation of an aggressive beast into a
real-life version of Ferdinand the Bull, the gentle hero of the popular children's
story.

In other
experiments, Delgado manipulated the limbs and emotions of cats, monkeys,
chimpanzees, and humans (most of them mental patients) with implanted
electrodes. In 1969, he extolled the potential benefits of brain-stimulation
technologies, which would help us create "a less cruel, happier, and better
man." In the 1970s, brain-implant research got bogged down in technical and
ethical issues, but it has recently made a comeback, as scientists have begun
exploring the potential of implanted devices for treating epilepsy, depression,
paralysis, and other disorders of the nervous system. The Pentagon has become a
major funder of research on brain-implant devices, which could in principle
boost soldiers' physical and mental powers -- and make them easier for
commanders to control. This technology raises an obvious question: Who gets the
brain implant, and who gets the remote controller?

In the heyday of
eugenics in the late nineteenth and early twentieth centuries, some scientists
and commentators proposed that we reduce our aggression through selective
breeding, just as breeders of dogs, cats, cattle, and other domestic animals
have done. The Nazis gave eugenics a bad name, but recent research on genes
associated with inherited diseases has resuscitated the idea that we can engineer
ourselves to be nicer. Another possibility, say some, is pacifying people with
drugs called serenics. One possible candidate is the hormone oxytocin, which
has been linked to primates' feelings of affection and trust.

Other
bio-solutions are cultural rather than strictly physiological. In his 1906
essay "The Moral Equivalent of War," William James suggests channeling young
men's martial urges into a "war against nature," which would entail fishing,
logging, digging tunnels, and other risky, invigorating work. The biologist and
Nobel laureate Konrad Lorenz, in his 1963 book On Aggression, proposes that
societies vent their aggression through "sporting contests" both within and
between nations. Some scholars have taken this proposal seriously enough to test
it, and they have found no correlation between societies' propensity for war
and their fondness for sports.

If more sports
doesn't make us less violent, what about more sex? During the 1960's,
counterculture pundits claimed that imperialism, fascism, totalitarianism, and
other forms of violent social control stemmed from repressed sexual desire. The
implication of this hypothesis -- expressed in the hippy slogan "Make love, not
war" -- was that more sex would mean less war. This meme has been revived by
research on the sexy, peaceful bonobos. But there is no evidence that violent
human societies engage in less sex than peaceful ones, or vice versa. If anything,
some men and women find war sexually arousing.

The most serious bio-solution
entails giving women more responsibility in contemporary human culture. Because
innate male aggression is the primary cause of war, the reasoning goes, bestowing
more political power on women will decrease the risk of war. But women are not
innate pacifists any more than men are innate warriors. Joan of Arc, Queen
Elizabeth I, Catherine the Great, Margaret Thatcher, Golda Meir, and Indira Gandhi
were formidable war leaders. Although 99 percent of the combatants in all wars
have been male, women can also make ferocious warriors if given the
opportunity. One remarkable example is a female regiment founded in the
eighteenth century in the west African kingdom of Dahomey (now Benin). In 1727,
a Dahomean King formed an all female troop that included as many as six
thousand women and lasted until 1892, when France conquered Dahomey. The women
warriors were renowned for their courage and cruelty. Their favorite weapon was
a gigantic folding razor with a blade over two feet long, with which these
soldiers decapitated and castrated enemies.

During World War
I, a Russian peasant named Maria Botchkareva organized a female "Battalion of
Death" consisting of several hundred female soldiers. Russian leaders hoped that
the female warriors would inspire, or shame, males to fight more boldly against
the German army. The tactic failed. The female fighters mounted several
advances on German positions, but few of their exhausted, demoralized male
comrades joined them. Botchkareva complained bitterly that "the men knew no
shame."

Women have
contributed to war indirectly as well. During World War I, women in England and
America organized a campaign to shame men into joining the war effort. The
women carried white feathers in their pockets and thrust them at men dressed in
civilian clothes. After they received the vote in the U.S. and elsewhere, women
did not favor less hawkish leaders and policies (as some male opponents of
suffrage had feared).

The link between
war and male dominance -- like the link between war and every other factor -- is
tenuous. Some male-dominated societies are peaceful. Women only obtained the right
to vote in war-averse Switzerland in the 1990s. Conversely, the United States
has remained militaristic over the past century in spite of making progress in
the direction of gender parity.

Biologically-based
solutions cannot solve war, any more than biologically-based theories can
explain it. "We would be lucky," the political scientist Joshua Goldstein
remarks in his 2001 book War and Gender, to find that war is totally determined
by our biology. We could just "find the hormone or neurotransmitter" that
inhibits lethal behavior and "add it to the water supply like fluoride.
(Instant peace, just add water.) Unfortunately, real biology is a lot more
complicated and less deterministic."